Preparations and applications of novel copolymeric adsorbents for selective removal of endotoxin

制备了一种新型的共聚物吸附剂，用于从酸性蛋白质溶液中选择性去除内毒素。吸附剂包含衍生自N，N-二甲基氨基丙基酰胺（DMAPAA）和二乙烯基苯（DVB）的球形共聚物。当DMAPAA与DVB的摩尔比为80/20（氨基含量：5.1 meq/g），孔径（多糖的分子量排除，M_<lim>）为4000至10000时，DMAPAA/DVB在pH 5.0至9.0和离子强度μ = 0.05至0.4时显示出高的内毒素吸附活性。吸附剂（M_<lim>：4，000）的容量为390 mg内毒素（从大肠杆菌O_（111）：B_4纯化的脂多糖）/ml吸附剂。内毒素和吸附剂之间的表观解离常数为2.2 × 10-12 M。另一方面，吸附剂对牛血清白蛋白（一种酸性蛋白）的吸附随Mlim从4，000增加至10，000而增加，但随离子强度（mu）从0.05增加至0.2而减少。结果表明，DMAPAA/DVB（80/20）（M_<lim>：4，000）在pH7.0和m = 0.05条件下可选择性地从各种酸性蛋白质溶液中去除内毒素。蛋白质溶液中的内毒素残留浓度始终降至0.1ng/ml以下，蛋白质的回收率大于97%。

Novel copolymeric adsorbents for selective removal of endotoxin from an acidic protein solution were prepared. The adsorbents comprise spherical copolymers derived from N,N-dimethylaminopropylamide (DMAPAA) and divinylbenzene (DVB). When the molar ratio of DMAPAA to DVB was 80/20 (amino-group content : 5.1 meq/g) and the pore size (molecular mass exclusion of polysaccharide, M_<lim>) was 4000 to 10000, DMAPAA/DVB showed a high endotoxin-adsorbing activity at pH 5.0 to 9.0 and ionic strengths of mu = 0.05 to 0.4. The capacity of the adsorbent (M_<lim> : 4,000) was 390 mg of endotoxin (lipopolysaccharide purified from E.coli O111 : B4) per ml of the adsorbent in the batchwise method. The apparent dissociation constant between endotoxin and the adsorbent was 2.2 X 10-12 M.On the other hand, the adsorption of bovine serum albumin, an acidic protein, by the adsorbent increased with increase in Mlim from 4,000 to 10,000, but decreased with increase in the ionic strength (mu) from 0.05 to 0.2. As a result, DMAPAA/DVB (80/20) (M_<lim> : 4,000) selectively removed endotoxin from various acidic protein solutions at pH 7.0 and m = 0.05. The residual concentration of endotoxin in the protein solution always decreased to a concentration lower than 0.1 ng/ml and the recovery of the protein was over 97%.